Expanding Canonical Spider Silk Properties through a DNA Combinatorial Approach

Area of Science:

• Biomaterials Science
• Protein Engineering
• Genomics

Background:

• Spider silk properties vary due to diverse repetitive core domains in silk genes.
• Previous research focused mainly on dragline silk proteins (MaSp1, MaSp2).
• Understanding other silk protein domains is crucial for expanding biomaterial applications.

Purpose of the Study:

• To establish gene libraries from *Latrodectus hesperus* repetitive core regions.
• To characterize the structural and mechanical properties of novel recombinant silk proteins.
• To explore the potential of these proteins as building blocks for advanced biomaterials.

Main Methods:

• Construction of two gene libraries (Library A and Library B) from *Latrodectus hesperus* silk genes.
• Expression and purification of recombinant proteins.
• Analysis using Fourier Transform Infrared Spectrometry (FTIR) for structural characterization (β-sheet, β-turn, random coil).
• Mechanical property assessment via Atomic Force Microscopy (AFM) on protein films.

Main Results:

• Recombinant proteins from Library A (e.g., *masp1*/*masp2*, *acsp1*/*tusp1*) showed higher β-sheet content than dragline silk proteins.
• Recombinant proteins from Library B (*pysp1*, *flag*) exhibited higher β-turn and random coil content.
• Films from Library A proteins demonstrated higher elastic moduli compared to Library B.
• Both libraries yielded recombinant proteins with superior elastic moduli versus native spider silk.

Conclusions:

• Repetitive core regions of *Latrodectus hesperus* silk genes can be utilized as versatile building blocks.
• This approach allows for the creation of novel silk-based biomaterials with tunable mechanical properties.
• The findings open avenues for developing advanced materials with tailored performance characteristics.